Anatomy and physiology of the male urethral sphincter and its preservation in prostatic surgery

Abstract

Radical prostatectomy is commonly used in the management of localized prostate cancer. Urinary incontinence after prostatectomy is of great concern to many patients. Improved understanding of the anatomy of the external urethral sphincter complex has resulted in a statistically significant decrease in the incidence of postprostatectomy incontinence. Most recent anatomic studies have described the external urethral sphincter complex as consisting of an intrinsic rhabdosphincter surrounding the smooth musculature of the urethra and an extrinsic sphincter incorporating the levator ani muscle and the pelvic floor. Both form a condensed striated muscle ring around the membranous urethra. Preservation of as much as possible of the normal anatomy of the sphincter mechanism and its nerve supply results in an excellent return to continence after radical prostatectomy.